Square root and def function?

Question

As I've progressed a little more in Python I thought I would try out the define function. I've made this simple square root calculator. Please explain as simple as you can?

import math

def mathprob(x):
    math.sqrt(x)

yn = input()
num = int(input("Enter number to be square rooted."))

if yn == 'sqrt':
    ans = mathprob(num)
    print(ans)

elif yn == '':
    print("bye! :(")
    quit()

Answer 1

You need to return the value from your function, otherwise it returns None:

def mathprob(x):
     return math.sqrt(x)

Answer 2

You need to actually return something from your function, you can do it like this:

def mathprob(x):
    return math.sqrt(x)